<!DOCTYPE html>
<html lang="zh_CN">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<form action="http://localhost:8080/06_servlet/hello3" method="post">
    <input type="hidden" name="action" value="login" />
    <input type="hidden" name="username" value="root" />
    <input type="submit">
</form>
</body>
</html>